In general ship operation, there is a basic requirement that any water which lands on the deck of a ship be drained to prevent the accumulation of such water. Typically, the water is discharged through scuppers into the water below. Inevitably, and especially in connection with the operation of oil tankers, pollutants, such as oil, are also present on the decks of the ship and are also discharged. While it is desirable to remove all liquids from the deck of the ship, current environmental concerns render discharge of oil into the water below undesirable, if not illegal.
As such, the typical scupper arrangement is unsatisfactory. Typically, a scupper system includes a plurality of passageways leading from the deck of the ship to the side of the ship and open thereto. Either a manually moveable plug or hinged one-way doors within the scupper regulate the flow through the scupper. These previous scupper arrangements allow all liquids present on the deck of the ship to be discharged, and are incapable of discriminating between oil and water, for example.
In the case of the manually removable scupper plug, there is the added inconvenience of having to remove and replace the plug whenever any discharge of liquid is desired.